28 December 2009

Now with twice as many 0's and 1's

The GSM algorithm, technically known as the A5/1 privacy algorithm, is a binary code — which is made exclusively of 0's and 1's — that has kept digital phone conversations private since the GSM standard was adopted in 1988.

But the A5/1 algorithm is a 64-bit binary code, the modern standard at the time it was developed, but simpler than the 128-bit codes used today to encrypt calls on third-generation networks. The new codes have twice as many 0's and 1's.

That last statement, while technically true, is remarkably vacuous—even when compared to other sentences in the same article. To an uninitiated reader it gives no hint as to the relative complexity of the two codes (a 128-bit code being 18 billion billion times harder to guess in the absence of any other vulnerabilities).

Disclosure

I'm a software engineer at DNAnexus, Inc. This blog represents the opinion of myself and no one else.Unless specifically noted otherwise, I do not receive free review copies of books or other products mentioned here.